Loyalty a one-way street

I've been a loyal customer for many years and mostly happy customer too even though there have been hiccups in service coverage. I just loved the quick and efficient customer service, and how the my phone worked so seamlessly when I travelled abroad. 
However, over the past few days, I've been having one of the worst customer service experiences with T-Mobile making me question whether my loyalty is really a one-way street! I've spent multiple hours on chat and on phone with customer service and the problems are still not resolved.
It all started when I tried to upgrade the iPhone 11 in one of my lines to an iPhone 14 Pro (the line is upgrade eligible). First of all, my online account wouldn't let me make any changes online (it's been like that for a long while despite multiple appeals to fix it). So, I had to either use online chat or call in. I explained over chat but after some time I stopped getting responses and eventually signed out.
Then, I called 611. I spent nearly an hour. Here, I learned about a couple of issues. First, my account is not eligible for upgrade offer of $800 off for the iPhone 14 pro. Only the Magenta Max is. So, I agreed to make that leap. However, the price for the Max plan was more than what's quoted online. I've 3 lines, and Max shows $47 ($141 for the whole plan) per line. But, on the phone, I was told it would cost me $170. I didn't get a clear reason as to why I can't get that $141 rate. Secondly, the company that I work for offers an employee discount of 15% but the rep on the phone couldn't tell me why she couldn't put that in. She was checking with a supervisor and a long time went in that. I finally gave up after about an hour as I had to step out. She said she'll have a supervisor call me back with all the information.
 As I didn't get any call back, I called 611 the next day. I had to explain everything again. This time I was told that the Magenta Max 3 lines for 141 is available only for new customers. For existing ones, it is 170. I finally swallowed that and agreed to make that change just to get the iPhone 14 Pro discount. Again, after spending an hour and 15 minutes, the operator still couldn't make that change. He kept saying something wrong with my account and it is blocked from making changes. After this much time, I gave up and have asked him to call me back when ready. 
Another problem is the employee discount. My employer's page shows 15% discount. However, I called T-Mo Work Perks line for existing T-Mo customers. I was told my line may not be eligible. In that case, can I not convert my account to a personal account and get the discount? No, then, you've to add a new line. Now I learned that is available only if I add ANOTHER NEW LINE. I already have 3. How much more do I need? Another way T-Mo screws over existing customers.
Finally, after more than 2 hours with customer service on the phone and another hour on chat, I’m nowhere close to a resolution!
All these started due to my need for the iPhone 14 Pro upgrade. Verizon is offering that for free with iPhone 11 trade-in along with 500 for each of the lines I'm switching. I'll be switching a total of 4 lines, so that makes it very lucrative deal for me. T-Mo is making me jump through hoops. I'm so frustrated and tempted to jump ship. The only reason I was sticking to T-Mo was because it works seamlessly when I travel abroad. If this continues, I'll finally give up T-Mo, international or not.
TL; DR - 1) I want iPhone 14 Pro upgrade for free (or at least the $800 off) 2) I want 3 lines for 141 on Magenta Max. Why is that only for new customers? If not possible, and it is only available for $170, then, at least give me 15% employee discount without having to add another unwanted line 3) I want to be able to make changes online (Is that too much to ask? I keep getting this message that I can't make changes online! Why?!). Come on, give some reward for customer loyalty!!